In a conventional receiver, a first antenna element is disposed on one surface of a case, and a second antenna element is disposed on the other surface. The first antenna element and the second antenna element are fixed to a rotation shaft and unitized. The rotation shaft penetrates the case from the front surface to the rear surface, and the first antenna element and the second antenna element support the case (for example, Patent literature 1 (FIG. 8)).
However, the technology disclosed in Patent literature 1 is related to a receiver that can use one of two different types of antenna elements: a first antenna element formed in a zigzag shape on a dielectric plate, and a second antenna element formed linearly on a dielectric plate. Therefore, this technology cannot be directly applied to a receiver simultaneously using a plurality of antennas, disadvantageously.
In the antenna disclosed in Patent literature 1, a rotation shaft of the antenna is shared, and two antenna elements are disposed on the front surface and the rear surface of the case. The rear surface is difficult to be seen by a user, and hence the first antenna element is easily disposed on it. However, the front surface of the receiver has a large screen display section for displaying television programs. The side surfaces and top surface of the receiver have operation buttons, operation dials, input/output terminals, and ventilation/exhaust holes. Therefore, it can be difficult to dispose the second antenna element on the receiver. The arrangement of the antenna elements can be difficult depending on the structure of the case.
Patent literature 1 does not disclose a structure where a plurality of antenna elements is disposed on the surface of the same side of the case, for example on the rear surface of the case.